The Prodrive team yesterday confirmed their long-term commitment to Formula One while explaining further why they will not be racing as intended in 2008. Their entry has been hamstrung by a major problem facing the sport's power brokers, Bernie Ecclestone, the Formula One rights holder, and Max Mosley, the president of the ruling FIA: the vexed question of "customer" cars.

This year Toro Rosso and Super Aguri ran virtually identical versions of cars raced by Red Bull and Honda, though both face a legal challenge from Force India F1 (*é Spyker), who had to build their own cars as specified in the Concorde Agreement, which expires on 31 December.

Ecclestone and Mosley had expected a new agreement, due to commence on 1 January, to address that problem, but resistance from Spyker, and Williams, who had taken legal action to block Prodrive's entry, has so far stymied that.

Prodrive, which also runs the successful Subaru effort in the World Rally Championship, had intended to enter Formula One next year. "Over the past 18 months we have put considerable effort into securing an agreement for the supply of cars and engines from McLaren and Mercedes, as well as financial backing from a partner new to the sport," Prodrive said. "It was therefore particularly disappointing to face a last-minute legal challenge to our entry.

"This legal challenge and continuing delays to the new 'Concorde Agreement' represent a fundamental change in circumstances, therefore we must rule out the possibility of Prodrive being on the grid in 2008."